共查询到20条相似文献,搜索用时 11 毫秒
1.
L. Vannucci U. Abbondanno M. Bettiolo M. Bruno N. Cindro M. D'Agostino P. M. Milazzo R. A. Ricci G. Vannini 《Zeitschrift für Physik A Hadrons and Nuclei》1994,349(3-4):223-225
Excitation function and angular distributions of the62Ni(58Ni,58Ni)62Ni elastic scattering have been measured at incident58Ni energies from 220.0 to 230.0 MeV in steps of 0.5 MeV. Evidence of two structures was found in the excitation function; a statistical analysis suggests a possible nuclear cluster quasi-molecular nature for these structures. 相似文献
2.
L. Vannucci U. Abbondanno M. Bettiolo M. Bruno N. Cindro M. D’Agostino P. M. Milazzo R. A. Ricci T. Ritz W. Scheid G. Vannini 《Zeitschrift für Physik A Hadrons and Nuclei》1996,355(1):41-54
Excitation functions and angular distributions of58Ni+58Ni and58Ni+62Ni scattering at energies just above the Coulomb barrier have been measured aroundθ cm=90° in energy stepsΔE cm=0.25 MeV fromE cm ? 110 MeV toE cm ? 120 MeV for58Ni+58Ni and fromE cm ? 110 MeV toE cm ? 118 MeV for58Ni+62Ni. Evidence for structure of non-statistical character has been found in the angle-summed excitation functions; this evidence is corroborated by the analysis of the angular distributions. This is the first time that non-statistical structure in elastic and inelastic scattering is reported with high confidence level for this mass and excitation energy ranges. Attempts are presented to understand the nature of this structure, including the presence of intermediate dinuclear states and virtual states in a potential well. 相似文献
3.
S. J. Skorka A. M. Stefanini G. Fortuna R. Pengo W. Meczynski G. Montagnoli A. Tivelli S. Beghini C. Signorini P. R. Pascholati 《Zeitschrift für Physik A Hadrons and Nuclei》1987,328(3):355-362
Sub-barrier fusion excitation functions of35,37Cl+58,64Ni have been measured. They are discussed in comparison to similar data of34,36S+58,64Ni with the aim of revealing the influence of coupled proton transfer channels. Using the simplified coupled channel code CCFUS, differences in the effects of inelastic channels are eliminated in an approximative manner to stress the differences in the effects of transfer channels. Signatures of positiveQ-value transfer channels coupled to fusion are clearly identified. 相似文献
4.
H. Clement R. Frick G. Graw P. Schiemenz N. Seichert 《Zeitschrift für Physik A Hadrons and Nuclei》1983,314(1):49-53
The 2 1 + -excitation of deformed nuclei by tensor polarized deuterons provides an alignment of both nuclei and thus a means to study specifically the quadrupole-quadrupole interaction between both nuclei. The tensor analyzing powerA xz (θ) has been measured for the elastic and inelastic scattering on24Mg and28Si. The coupled channel analysis including a deformed tensor potential reveals a clear signature of the quadrupole-quadrupole part of the nuclear projectile-target interaction. 相似文献
5.
D. Axen G. Duesdieker L. Felawka Q. Ingram R. Johnson G. Jones D. Lepatourel M. Salomon W. Westlund L. Robertson 《Nuclear Physics A》1976,256(3):387-413
The interaction of 47.5 (±0.5) MeV positive pions with douterons was studied using a scintillation counter telescope as the pion spectrograph. With an energy resolution sufficient to separate the elastic from inelastically scattered pions, the system was used to measure the cross sections for these reactions as well as the non-radiative pion capture process over the angular range of 22.5°–157.5°. The scattering results are well-fitted by recent theoretical calculations provided appropriate pion-nucleon phase shifts are used. The protons from the non-radiative capture reaction are fitted by a differential cross section of the form: , with A = 0.31 ± 0.03. 相似文献
6.
S. Yu. Kun U. Abbondanno M. Bruno N. Cindro M. D’Agostino P. M. Milazzo R. A. Ricci T. Ritz B. A. Robson W. Scheid A. V. Vagov G. Vannini L. Vannucci 《Zeitschrift für Physik A Hadrons and Nuclei》1997,359(2):145-148
Structures of non-statistical character, recently observed in 58 Ni +46 Ti elastic and 58 Ni +62 Ni elastic and inelastic excitation functions, produce damped oscillations in the cross section energy autocorrelation functions. The analysis of these damped oscillations in terms of S-matrix spin and parity decoherence indicates, as a possible interpretation, damping of the coherent rotational motion of the intermediate dinuclear system formed in the reaction. 相似文献
7.
Z. Moroz P. Zupranski R. Böttger P. Egelhof K.-H. Möbius G. Tungate E. Steffens W. Dreves I. Koenig D. Fick 《Nuclear Physics A》1982,381(2):294-316
Elastic and inelastic scattering of aligned 7Li on 58Ni was studied experimentally for several energies between 14 and 22 MeV. Complete sets of second-rank tensor analyzing powers were measured for two energies, 14.2 and 22.0 MeV. The shape-effect model has been used for a qualitative interpretation of the data. The success of this model indicates the spectroscopic deformation of 7Li to be the main source of the observed second-rank tensor analyzing powers. The result enters the formulation of the diffraction as well as the optical model both of which are used to improve the analysis of the data. Besides the parameters which determine the central interaction the spectroscopic deformation was the only adjustable parameter. The deformation was found to be negative, in agreement with the oblate shape of 7Li. However the extracted value of the deformation varies within a factor of two when comparing different experiments and/or analyses with different models. The second-rank tensor analyzing powers for projectile excitation are roughly explained by the assumption that the angular momentum transfer is perpendicular to the momentum transfer. 相似文献
8.
Polarization parameters have been determined for deuteron elastic scattering from 27Al, Si and 60Ni at energies between 7 and 11 MeV and laboratory scattering angles from 30° to 135°. The vector polarization, iT11, and two tensor parameters T20 and T22, were measured by scattering polarized and unpolarized deuterons which were obtained from a tandem accelerator. The largest polarization was |iT11| ≈ 0.3 and |T20| ≈ 0.2 for 27Al at 11 MeV. For 60Ni, the observed polarizations were substantially smaller. Angular distributions of the unpolarized cross section were also measured for 27Al and Si. An optical-model analysis of the polarization and cross-section data was performed. The vector polarization was reproduced reasonably well by a vector spin-orbit coupling of similar strength as found for nucleon scattering. A tensor interaction appears to be needed to account for the observed tensor polarizations. 相似文献
9.
《Nuclear Physics A》1998,628(1):1-16
High precision fusion excitation functions have been measured for the 16O+58Ni and 16O+62Ni systems from which fusion barrier distributions have been evaluated. Coupled-reaction-channels (CRC) calculations, which describe elastic and quasi-elastic scattering, also satisfactorily reproduce the fusion cross sections and barrier distributions. The small value of Z1Z2 in this case leads to barrier distributions with relatively little structure. However, in conjunction with the detailed elastic scattering data for these systems, this allows us to elucidate the role of previously ignored states in 16O in pushing the entire distribution to lower energies. These shifts are consistent with derived magnitudes of polarization potentials for both systems. 相似文献
10.
The radial distribution of gold nuclei obtained by evaporation in UHV onto alkali halide surfaces is measured, and is analysed in terms of parameters such as the nature of the substrate and the mean diameter of nuclei. This analysis seems to prove the presence of repulsive elastic forces between nucleus pairs due to the overlap of the strain fields induced by the nuclei in the substrate. 相似文献
11.
Nuclear-interaction potentials that are calculated by using Skyrme forces within the extended Thomas-Fermi approximation and Hartree-Fock-Bardeen-Cooper-Schrieffer theory are studied in detail. It is shown that the nuclear component of the potential simulating the interaction between nuclei grows with increasing number of neutrons in colliding isotopes and with increasing diffuseness parameter of the density distribution in interacting nuclei. An increase in the diffuseness parameter of the density distribution in interacting nuclei leads to a decrease in the height of the barrier between the nuclei and to an increase in the depth of the capture well and in the fusion cross section. It is shown that the diffuseness parameter calculated for the nuclear component of the potential at large distance between interacting nuclei by using Skyrme forces exceeds the diffuseness parameter of the nucleon-density distribution in these nuclei by a factor of about 1.5. Realistic values of the diffuseness parameter of nuclear interaction between medium-mass and heavy nuclei fall within the range a ≈ 0.75–0.90 fm. 相似文献
12.
F. Frisone 《Il Nuovo Cimento D》1996,18(11):1279-1285
Summary In this work we have studied the influence of the impurity concentration on the phenomenon of fusing of deuterons, catalyzed
by the ?efficacious? interaction with the plasmons of the metal. The numeric calculation, conducted on different metals considering
the degree of impurities present in the reticulum, shows that the probability of fusion is amplified by the impurities. This
result is confirmed qualitatively by the trend of the potential gap that describes the interaction inside the metal. 相似文献
13.
W. Scobel J. Bisplinghoff M. Blann A. Mignerey P. David J. Ernst T. Mayer-Kuckuk 《Zeitschrift für Physik A Hadrons and Nuclei》1978,284(3):343-350
Elastic scattering angular distributions for35Cl from27Al,58, 62Ni,116, 120, 124Sn and141Pr have been measured at energies between 100 and 170 MeV. Optical model analyses have been performed to determine reaction cross sections, strong absorption radii and grazing angular momenta. The results are compared with the corresponding quantities extracted by means of the Fresnel scattering model. Near the interaction barrier the quarter point method yields reaction cross sections systematically smaller than the optical model results. The interaction radii, however, do not show significant differences or energy dependencies. These radii are compared with trend formulae for interaction radii, and comparisons with fusion radii are made. 相似文献
14.
L.S. AzhgireiZ. Cisek Z.V. KrumsteinYu.P. Merekov Z. MorozNgo Quang Zui V.I. PetrukhinA.I. Ronzhin G.A. Shelkov 《Nuclear Physics A》1972
The spectra of deuterons emitted at angles of 6.5°, 9.5°, 13.5° and 16° (lab system) in the interaction of protons with the nuclei 1H, 2H, 6Li, 7Li, C, Al, Cu, Rh and Pb have been measured in the momentum range 700–1700 MeV/c. The secondary particles were analyzed with the help of magnetic and time-of-flight spectrometers. The differential cross sections for deuteron production in the reactions p + 〈2N〉 → N + d and p + 〈N〉 → d + π have been measured for selected nuclei and angles. The effective numbers of nucleons and of two-nucleon clusters for the investigated nuclei were determined. The results obtained are discussed in terms of the dispersion theory of direct nuclear reactions. 相似文献
15.
V. V. Dyachkov N. T. Burterbaev A. V. Yushkov 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(8):895-900
The angular distributions of 18 MeV deuterons elastically scattered on 9Be, 10B, 13C, 24Mg, and 25Mg nuclei are measured using the U-150M cyclotron at the Institute for Nuclear Physics (Almaty, Kazakhstan). The free parameters of the scattering matrix of parametrized phase analysis are determined. We estimate the sign of the nucleus??s deformation for even nuclei 64Ni, 64Zn, 144Sm, 182W, 184W, 192Os, 238U, and odd nuclei 59Co, 63Cu, 89Y, 93Nb, 103Rh, 107Ag, 181Ta, 197Au, 205Tl, and 209Bi. 相似文献
16.
In recent years,multinucleon transfer reactions have attracted significant attention for their potential to synthesize new exotic nuclei.These nuclei are difficult to be produced in fusion-evaporation reactions and fragmentation processes due to the extremely small production cross sections and/or the lack of appropriate projectile-target combinations.In the early 1970s,multinucleon transfer reactions have been used for the production of the light neutron-rich isotopes [1]. 相似文献
17.
J. Giovinazzo B. Blank C. Borcea M. Chartier S. Czajkowski G. de France R. Grzywacz Z. Janas M. Lewitowicz F. de Oliveira Santos M. Pfützner M.S. Pravikoff J.C. Thomas 《The European Physical Journal A - Hadrons and Nuclei》2001,10(1):73-84
Decay studies of very neutron-deficient nuclei ranging from 39Ti to 49Ni have been performed during a projectile fragmentation experiment at the GANIL/LISE3 separator. For all nuclei studied in
this work, 39, 40Ti, 42, 43Cr, 46Mn, 45, 46, 47Fe and 49Ni, half-lives and decay spectra have been measured. In a few cases, γ coincidence measurements helped to successfully identify
the initial and final states of transitions. In these cases, partial decay scheme are proposed. For the most exotic isotopes,
39Ti, 42Cr, 45Fe and 49Ni, which are candidates for two-proton radioactivity from the ground state, no clear evidence of this process is seen in
our spectra and we conclude rather on a delayed particle decay.
Received: 26 July 2000 / Accepted: 20 December 2000 相似文献
18.
The cross sections have been measured in the energy range of interest for stellar nucleosynthesis during oxygen and silicon burning. The results are compared with statistical theory calculations which attempt to treat excited state effects and the γ-ray channel more realistically than previous calculations. 相似文献
19.
Rudolph D Carlsson BG Ragnarsson I Aberg S Andreoiu C Bentley MA Carpenter MP Charity RJ Clark RM Cromaz M Ekman J Fahlander C Fallon P Ideguchi E Macchiavelli AO Mineva MN Reviol W Sarantites DG Seweryniak D Williams SJ 《Physical review letters》2006,96(9):092501
High-spin states in 58Ni have been investigated by means of the fusion-evaporation reaction 28Si(32S, 2p)58Ni at 130 MeV beam energy. Discrete-energy levels are observed in 58Ni at record-breaking 42 MeV excitation energy and angular momenta in excess of 30h. The states form regular rotational bands with unprecedented high rotational frequencies. A comparison with configuration dependent cranked Nilsson-Strutinsky calculations reveals an exceptional two-band crossing scenario, the interaction strength of which is strongly shape dependent. 相似文献